1. Spectroscopic Investigation of o-, m-, and p-Cyanostyrenes International Symposium for Molecular Spectroscopy FE-12 Joseph A. Korn †, Stephanie N. Knezz ‡, Robert J. McMahon ‡, and Timothy S. Zwier † † Department of Chemistry, Purdue Univesity, West Lafayette, IN, USA ‡ Dept. of Chemistry,University of Wisconsin, Madison, WI, USA The Zwier Lab

2. Titan’s Atmosphere – Hydrocarbons and Nitrogenated hydrocarbons – Cassini-Huygens mission Pathways to Tholins – Subsituted Aromatics – C 2 H 2 /C 3 HN addition – Ring-closing mechanisms Photochemical/Discharge driven pathways Introduction 1.Waite Jr., J.H.; et al.,Science, 2007. 316, 870-875 2.Landera, A.; Mebel, A. M. Journal of the American Chemical Society 2013, 135, 7251.

3. Isomers of Quinoline (C 9 H 7 N, 129 amu) – Isoquinoline – (E)/(Z)-Cinnamonitrile – o-,m-,p-Cyanostyrene Analogous Studies – Naphthalene photochem – o,-m-,p-Ethynylstyrene Isomer specific pathways to larger polyaromatic nitrogenated heterocycles (PANHs) Introduction 1.Landera, A.; Mebel, A. M. Journal of the American Chemical Society 2013, 135, 7251. 2. Sebree, J.; et al., Journal of the American Chemical Society 2012, 134, 1153. 3. Selby, T. M.; et al., The Journal of Physical Chemistry A 2005, 109, 4484 Cis-o-CyanostyreneIsoquinoline ?

4. Experimental Methods (R2PI) Ionization Continuum S0S0 SnSn Tuned Laser Ionization Laser (193 nm) Laser Port TOF MS Einzel Lens 2-Stage Ion Acceleration Jordan Valve Boltzmann distribution of vibrational population prior to expansion Collisional cooling to zero-point vibrational level A A B B UV High pressure helium A A B B C C C C C A A A A A A A B B B B B B B C C C C C Supersonic Expansion

5. Experimental Methods (LIF/DF) S0S0 SnSn Fluorescence Dispersed

6. 10 Hz scanned holeburn laser 20 Hz fixed probe – Δt~200 ns Active baseline subtraction – Conformation specific UV spectrum Experimental Methods (UV-Depletion)

7. Para-Cyanostyrene (p-CNs:Excitation) S1S1 ModeExperimentalCalculated * ν 20 11751187 ν 24 (6a/X)760787 ν 27 (6b)512549 ν 29 (6a/X)332369 ν 30 239240 ν 31 102139 ν 44 143145 ν 45 5157 29 1 0 (6a/X) A-axis 33923 cm -1 24 0 1 (6a/X) *B3LYP/6-31G+(d)

8. Para-Cyanostyrene (p-CNs: DF) S0S0 ModeExpt.Calc. ν 20 12141208 ν 24 (6a/X)827 ν 25 678686 ν 27 (6b)550562 ν 29 (6a/X)383 ν 30 234245 ν 31 134139 ν 45 3745

9. Para-Cyanostyrene (p-CNs: DF: Fermi Resonace)

10. Meta-Cyanostyrene (m-CNs: UV Depleton)

11. B3LYP/6-31+G(d) m-ethynylstyrene – Trans Calc.: -29 cm -1 Expt.: +75 to -81 cm -1 – Barrier to Isomerization Calc.: 1237 cm -1 Expt.: 990-1070 cm -1 Meta-Cyanostyrene (m-CNs) : Cis vs Trans 13.9 cm -1 1326 cm -1 Trans Cis 1. Selby, T. M.; et al., The Journal of Physical Chemistry A 2005, 109, 4484 Graphic not to scale

12. 25 1 0 (6b) B-axis Meta-Cyanostyrene (m- CNs: Conformer A: cis) S1S1 S0S0 ModeExpt.Calc.Expt.Calc. ν 18 1238125612481262 ν 23 (12)-98310081012 ν 25 (6b)667693714721 ν 26 -578570580 ν 28 (6a/X)443432466468 ν 29 (6a/X)-417434445 ν 30 299252-246 ν 38 625.9616-- ν 39 ν 40 974976-- ν 45 -934043 28 1 0 (6a/X) A-axis 29 1 0 (6a/X) 23 1 0 (12)

13. Meta-Cyanostyrene(m- CNs: Conformer B: trans) S0S0 ModeExpt.Calc. ν 18 12511266 ν 23 (12)10081012 ν 25 (6b)717723 ν 27 (6a/X)535549 ν 28 (6a/X)466470 ν 29 414419 ν 43 229210 ν 45 3853

14. Ortho-Cyanostyrene (o-CNs) : R2PI S 1 ←S 0 33074 cm -1

15. Cis 456 cm -1 over trans – E a =981 cm -1 trans-o- ethynylstyrene – k isom >k collision – Isomerization Barrier: 710 cm -1 – -696.4 cm -1 to cis Ortho-Cyanostyrene (o-CNs) : Cis preferred S1S1 S0S0 ModeExperimentalCalculatedExperimentalCalculated ν 19 (13)1205119812211214 ν 25 (1)682705727736 ν 26 596598-- ν 28 (6a/X)421426460456 ν 29 (6a/X)298402405426 ν 30 244243254249 ν 31 136139132145 ν 42 292287416393 ν 43 149187205210 ν 44 109101124125 ν 45 78653045 456 cm -1 981 cm -1 Trans Cis 1. Selby, T. M.; et al., The Journal of Physical Chemistry A 2005, 109, 4484

16. Ortho-Cyanostyrene (o-CNs) : DF Origin

17. Ortho-Cyanostyrene (o-CNs) : DF Mixed

18. Ortho-Cyanostyrene (o- CNs) : DF Fundamentals False Origin

19. Spectra of Cyanostyrenes are identified Cis/trans observed in m-CNs only 6a-type modes coupled to styrene/nitrile vibrations Duschinsky mixing is prevalent in S 1 Conclusions

20. Photoisomerization of cis-trans m-CNs Photochemistry of o-CNs to Isoquinoline Chirped Pulse Microwave study of o-CNs – Cis dipole moment: 4.4052 Debye – Trans dipole moment: 4.6386 Debye Future Work

21. Dr. Timothy S. Zwier Dr. Robert McMahon Zwier Lab McMahon Lab (Stephanie N. Knezz) Acknowledgements Funding: